Forest health professionals with the Missouri Department of Conservation (MDC) advise Missourians to watch for damage from an invasive tree pest in winter months. The Emerald Ash Borer (EAB) is a small, metallic green beetle native to Asia that attacks and kills ash trees.

EAB attacks all species of ash trees, and kills nearly every tree it infests. At approximately a half-inch long, the green adult beetle feeds on leaves and does very little damage to trees. However, in its larval stage, the insect kills ash trees by feeding on the water- and nutrient-conducting tissues just under the bark.

The destructive insect has been confirmed in 42 Missouri counties, as well as the City of St. Louis, and is suspected to be present in several more locations.

MDC encourages Missourians to watch for signs of this invasive pest during winter months. While birding, watching wildlife, hiking, or enjoying other outdoor pursuits this winter, keep an eye out for bark blonding on ash trees. Bark blonding is caused by woodpeckers removing a tree’s outer bark while searching for insect larvae. On ash trees, this feeding activity reveals a white inner bark that is highly noticeable. Ash trees with bark blonding may not have EAB, but it is certainly worth reporting these trees for a closer look by trained foresters.

“EAB is estimated to cost Missourians more than $180-million in tree treatments, removals, and replacements over the next 20 years,” said MDC Forest Entomologist Robbie Doerhoff. “If you have a healthy, high-value ash tree in your yard, it can be treated with insecticides that will protect it from EAB. However, these treatments can be expensive and must be applied every year or two to guarantee protection. For some ash trees, the best option is removal and replanting with a different species such as an oak native to Missouri.”

MDC encourages Missourians to help prevent the spread of this destructive pest by learning to identify signs of EAB and reporting possible infestations in counties where EAB has not yet been confirmed. For more information on insecticide treatments for ash trees, consult the Emerald Ash Borer Management Guide for Missouri Homeowners at short.mdc.mo.gov/ZSq.

For a map of EAB’s spread across Missouri, detailed information on identification, and a guide on insecticide treatments, visit eab.missouri.edu. Report suspected EAB damage in new counties to a local MDC forester, call MDC’s Forest Pest Hotline at 866-716-9974, or email [email protected]